Hunting Forum

Changes in Earth's atmosphere

There is considerable evidence that over the very recent period of the last 100–1000 years, the sharp increases in human activity, especially the burning of fossil fuels, has caused the parallel sharp and accelerating increase in atmospheric greenhouse gases which trap the sun's heat. The consensus theory of the scientific community is that the resulting greenhouse effect is a principal cause of the increase in global warming which has occurred over the same period, and a chief contributor to the accelerated melting of the remaining glaciers and polar ice. A 2012 investigation finds that dinosaurs released methane through digestion in a similar amount to humanity's current methane release, which "could have been a key factor" to the very warm climate 150 million years ago.[42]

There is evidence that greenhouse gas levels fell at the start of ice ages and rose during the retreat of the ice sheets, but it is difficult to establish cause and effect (see the notes above on the role of weathering). Greenhouse gas levels may also have been affected by other factors which have been proposed as causes of ice ages, such as the movement of continents and volcanism.

The Snowball Earth hypothesis maintains that the severe freezing in the late Proterozoic was ended by an increase in CO2 levels in the atmosphere, and some supporters of Snowball Earth argue that it was caused by a reduction in atmospheric CO2. The hypothesis also warns of future Snowball Earths.

In 2009, further evidence was provided that changes in solar insolation provide the initial trigger for the Earth to warm after an Ice Age, with secondary factors like increases in greenhouse gases accounting for the magnitude of the change.[43]

William Ruddiman has proposed the early anthropocene hypothesis, according to which the anthropocene era, as some people call the most recent period in the Earth's history when the activities of the human species first began to have a significant global impact on the Earth's climate and ecosystems, did not begin in the 18th century with the advent of the Industrial Era, but dates back to 8,000 years ago, due to intense farming activities of our early agrarian ancestors. It was at that time that atmospheric greenhouse gas concentrations stopped following the periodic pattern of the Milankovitch cycles. In his overdue-glaciation hypothesis Ruddiman states that an incipient glacial would probably have begun several thousand years ago, but the arrival of that scheduled glacial was forestalled by the activities of early farmers.[44]

At a meeting of the American Geophysical Union (December 17, 2008), scientists detailed evidence in support of the controversial idea that the introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe began to alter world climate by pumping significant amounts of greenhouse gases into the atmosphere over the last 1,000 years. In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming, possibly forestalling the onset of a new glacial age.[45]
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Changes in Earth's atmosphere

There is considerable evidence that over the very recent period of the last 100–1000 years, the sharp increases in human activity, especially the burning of fossil fuels, has caused the parallel sharp and accelerating increase in atmospheric greenhouse gases which trap the sun's heat. The consensus theory of the scientific community is that the resulting greenhouse effect is a principal cause of the increase in global warming which has occurred over the same period, and a chief contributor to the accelerated melting of the remaining glaciers and polar ice. A 2012 investigation finds that dinosaurs released methane through digestion in a similar amount to humanity's current methane release, which "could have been a key factor" to the very warm climate 150 million years ago.[42]

There is evidence that greenhouse gas levels fell at the start of ice ages and rose during the retreat of the ice sheets, but it is difficult to establish cause and effect (see the notes above on the role of weathering). Greenhouse gas levels may also have been affected by other factors which have been proposed as causes of ice ages, such as the movement of continents and volcanism.

The Snowball Earth hypothesis maintains that the severe freezing in the late Proterozoic was ended by an increase in CO2 levels in the atmosphere, and some supporters of Snowball Earth argue that it was caused by a reduction in atmospheric CO2. The hypothesis also warns of future Snowball Earths.

In 2009, further evidence was provided that changes in solar insolation provide the initial trigger for the Earth to warm after an Ice Age, with secondary factors like increases in greenhouse gases accounting for the magnitude of the change.[43]

William Ruddiman has proposed the early anthropocene hypothesis, according to which the anthropocene era, as some people call the most recent period in the Earth's history when the activities of the human species first began to have a significant global impact on the Earth's climate and ecosystems, did not begin in the 18th century with the advent of the Industrial Era, but dates back to 8,000 years ago, due to intense farming activities of our early agrarian ancestors. It was at that time that atmospheric greenhouse gas concentrations stopped following the periodic pattern of the Milankovitch cycles. In his overdue-glaciation hypothesis Ruddiman states that an incipient glacial would probably have begun several thousand years ago, but the arrival of that scheduled glacial was forestalled by the activities of early farmers.[44]

At a meeting of the American Geophysical Union (December 17, 2008), scientists detailed evidence in support of the controversial idea that the introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe began to alter world climate by pumping significant amounts of greenhouse gases into the atmosphere over the last 1,000 years. In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming, possibly forestalling the onset of a new glacial age.[45]
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OOOOPs, sorry about that fellers---nervous fingers
Allen

Posted By bigrig on 09 Mar 2013 01:13 PM
YH: You sure your not from the Yukon and your names not Cam?  Yukon Hunter used to play devils advocate and take the other side of a lot of debates on these boards.  You sure remind me a lot of him.

Yup, you called it... YH is Yukon/Cam.

"There are those who believe the poles will reverse"

CK, several years ago I watched a documentary on this subject on PBS. If I remember right Allen Alda was the narrator.

Ironically some of the science very much resembles the methodology of the climatologists. Instead of ice cores, they drilled lava cores. Theoretically  the metallic molecules frozen in the lava pointed either North or South during different time periods throughout history thus indicating a reversal of poles throughout history.

If the science is correct, according to the documentary,  we are overdue for a reversal of the the poles. Overdue by a good bit if I remember correctly.

Fact, the earth and all of the other planets are in declining orbits and are getting closer to the sun. Fact, the sun will eventually go super-nova, as it expands and it's gasses dissipate. Fact, at these actions occur each planet will warm up, until eventually they heat to the point of becoming molten rock prior to the sun's explosion in it's super-nova time. Fact, asteroids, meteors and meteorites, as well as the asteroid belt are the remnants of debris from other solar systems that have undergone the same scenarios as ours will eventually.

Statistically speaking, the global warming people claimed that the Polar Bear was declining in population due to the shrinkage of the ice, caused by green house gases which created this global warming phenomenon. Actually it's been proven that Polar Bear populations have actually increased. Seal populations have remained steady, even with the increases in Polar Bears, Killer Whales, and other natural predators (including man), in spite of the dire predictions that all of these creatures were in immediate danger of becoming extinct due to global warming.

Other than being used as a reason for increasing government spending, creating carbon credits, and adding more costs to consumers, global warming hasn't proven anything that isn't reflected in past studies conducted by previous generations of scientist who were just as concerned as any of today's group. If the excesses as claimed are going to destroy the planet in the next 10,000 years, then maybe it's a problem we should explore. Considering that the human race will probably destroy itself, long before that time, why should we really give a damn?

YH ummm 98%? Yeah not accurate at all. Actual numbers Nearly 100 scientists listed in Cato Institute ads in response to Obama's Nov 19 2008 speech where " the science is beyond dispute and the facts are clear" remark was made stated that the case for alarm is grossly overstated, that surface temp changes were episodic and modest over the last century and that the "hockey stick" computer model failed to explain why no new global warming had occurred in over a decade.

Time magazine 1920s warned of coming ice age, 1930s warned of global warming, 1970s approaching ice age and now back to warming.

National Snow and Ice Data Center found that Arctic sea ice EXPANDED 13.2% in 2008 ( about 270,000 square miles ). University of Illinois Arctic Climate Research Center has confirmed that the increase in global sea ice levels now equal those of 1979 ( the so called ice age year warning from Time and others ) and the increase since Sept 2008 has been the FASTEST since 1979.

Why did "global warming" morph in to "climate change" ? Maybe because temps DECREASED since 1998. More and more climatologists and other scientists started speaking out AGAINST global warming and blam new name! The fact that temps dropped since 1998 is undisputed in the scientific world and confirmed by many organizations such as the United Nations World Meteorological Organization, Department of Mathmatical Sciences at University of Wisconsin, Imperial College London astrophysicist and long range forecaster Piers Corbyn " according to official data in every year since 1998, world temperatures have been colder than that year, yet CO2 has been rising rapidly" Even Obama's own internal study on climate science written March 16 2009 by Alan Carlin ( sr operations research analyst at EPA's National Center for Environmental Economics ) confirmed this fact ( as well as that a particular rapid decline in 2007 - 2008 ) ( Obama suppressed the study and forbid him from having "any direct communication" with anyone outside his office. Somehow main stream media forgot to report much on this ( not a single tv news report )

Dr Martin Hertzberg ( physical chemist and retired Navy meterologist as well as life long LIBERAL Democrat ) wrote in USA Today ( Sept 26 2008 ) " As a scientist and life long liberal Democrat, I find the constant regurgitation of the anecdotal, fear mongering, clap-trap about human caused global warming to be a disservice to science. From the El Nino year of 1998 until January 2007, the average temperature of the Earth's atmosphere near its surface DECREASED some 0.25 C ( 0.45 F ). From January 2007 until the spring of 2008, it dropped a whopping 0.75 C ( 1.35 F )"

A normal, reasonable and open minded person could quite easily see that "man made global warming" is BS and political in nature, not science based. Since liberalism is a blinding disease that clouds one's vision and thought it is understandable that liberals cannot realize anything that is not spoon fed to them from their main stream masters.

Controlling people is what's this all about... stupid people become their victims.

BAHAHAHAHA!!!!!!
Using the Cato Institute as a reference? That's like using PETA to craft hunting regulations....
Get your collective heads out of your a$$es. The 98% figure is accurate- and if those 98% know it, I believe them.

Hmmmm, I thought you did use PETA to draft your hunting regs, based on all of your other tree hugging liberal stances. Perhaps, you should get your head out of Obama's ass!

YH is still kicking I see.

Only reason he supports Global Warming theiries is so Polar Bears will be declared Appendix I and First Nations will starve and he can go hunt aywhere without Native interference......
BTW, I do believe the Globe has warmed....otherwise we would still be in an Ice Age.....